Organ manipulator having suction member supported with freedom to move relative to its support

ABSTRACT

An organ manipulator including at least one suction member or adhesive disk mounted to a joint providing freedom of movement of the at least one suction member or adhesive disk relative to its support. A method for retracting and suspending an organ in a retracted position using suction (or adhesive force) so that the organ is free to move normally (e.g., to beat or undergo other limited-amplitude motion) in at least the vertical direction during both steps.

This application is a continuation of application Ser. No. 09/747,388filed Dec. 22, 2000, now U.S. Pat. No. 6,730,020, which is a division ofapplication Ser. No. 09/390,792 filed Sep. 7, 1999, now U.S. Pat. No.6,506,149 which issued on Jan. 14, 2003. Application Ser. Nos.09/747,388 and 09/390,792 and U.S. Pat. No. 6,506,149 are herebyincorporated herein, in their entireties, by reference thereto. Further,we claim priority under 35 USC § 120 to application Ser. Nos. 09/747,388and 09/390,792.

FIELD OF THE INVENTION

The invention pertains to an apparatus for manipulating (and supportingin a retracted position) an organ such as a beating heart. Preferredembodiments of the invention pertain to an apparatus for support andmanipulation of a beating heart during surgery thereon, in a mannerpromoting oxygenation during the surgery.

BACKGROUND OF THE INVENTION

Coronary artery bypass grafting (CABG) has traditionally been performedwith the use of a cardiopulmonary bypass (CPB) machine to oxgenate andperfuse the body during surgery. Recently, techniques have beendeveloped to allow for performing CABG without the use of CPB bystabilizing the epicardial surface of a beating heart at the coronaryanastomotic site with a stabilizer (e.g., stabilizing feet) to allowplacement of sutures through the graft vessel and recipient coronaryartery. This procedure may be performed through a partial or fullsternotomy, or via a thoracotomy (which is an incision between twoadjacent ribs).

Access to the left anterior descending (LAD) coronary artery is easilyperformed by either a sternotomy or a thoracotomy. However, the patienttypically requires bypass to multiple coronary arteries, including thecircumflex artery (CxA) on the left lateral aspect of the heart, theright coronary artery (RCA) on the right lateral aspect of the heart,and the posterior descending artery (PDA) on the back side of the heart.It is very difficult to access the CxA, RCA, and PDA without asternotomy, as the heart needs to be turned or tilted (or turned andtilted) significantly to reach its side or back, and with an intactsternum, insufficient space exists for these maneuvers. For example, theapex of the heart is generally lifted out of the body through asternotomy in order to reach the PDA. Surgeons often place the patientin a Trendelenberg position, with the operating table tilted so that thepatient's head lies lower than the feet with the patient in supineposition, in order to assist with lifting the heart up and back.

An additional challenge to beating heart surgery is that some hearts donot tolerate manipulation well from a hemodynamic standpoint. Thepotential exists with current manipulation techniques to compress theheart (e.g., by pressing it with stabilization feet) or great vessels insuch a way that hemodynamic function is compromised.

There is a need for a beating heart retraction apparatus capable ofphysically translating a beating heart from its natural resting place toa location better suited to surgical access, and then holding thebeating heart in the latter location during surgery without compressing(or otherwise deforming) the heart or great vessels in such a way thathemodynamic function is compromised.

Typically, beating heart surgery has been accomplished through a partialsternotomy using pericardial sutures to retract the heart into theproper position for surgery, and using a stabilization apparatus (e.g.,stabilizing feet) to stabilize the portion of the heart surface to becut. Sometimes, surgery is performed on the properly positioned heartwithout using a stabilization apparatus.

However, conventional use of pericardial sutures for retraction of abeating heart has limitations and disadvantages including the following.It is inconvenient and potentially harmful to the patient to incise thepericardium and insert sutures along cut edges of the pericardium, andthen exert tension on the sutures to move the heart together as a unitwith the pericardium. When the sutures are pulled to lift the heart(with pericardium), compressive force exerted by the pericardium on atleast one side of the heart sometimes constrains cardiac contraction andexpansion.

There are three distinct stages involved in preparing an artery (on anorgan) for anastomosis:

1. gross manipulation: the organ is physically translated from itsnatural resting place to a location better suited to surgical access;

2. artery presentation: the target artery on the organ is identified andthe position of the organ is finely adjusted so that the target arteryis approachable; and

3. artery stabilization: the target artery and surrounding tissues areimmobilized, allowing fine surgical techniques on very small features.

The present invention pertains to an improved method and apparatus forretraction (gross movement) of a beating heart or other organ into adesired position and orientation to allow surgery to be performed on theorgan. When the organ has been retracted (in accordance with theinvention) into a desired position and orientation, any of the manycommercially available tissue stabilization products (including thosemarketed by Guidant, Medtronic, CardioThoracic Systems, and Ethicon) canbe used to stabilize a portion of the organ's surface on which surgeryis to be performed. However, such tissue stabilization products cannotduplicate the function of the inventive apparatus. Retraction requireslifting and usually rotation of the organ. Devices designed specificallyfor tissue stabilization are not well suited to those motions.

One class of the stabilization devices commonly used to stabilize atarget portion of a heart surface (a portion on which surgery is to beperformed) are the stabilization devices that comprise rigid (C-shapedor linear) structures lined with suction cups, such as those describedin the article Borst, et al., “Coronary Artery Bypass Grafting WithoutCardiopulmonary Bypass and Without Interruption of Native Coronary FlowUsing a Novel Anastomosis Site is Restraining Device (“Octopus”), J. ofthe American College of Cardiology, Vol. 27, No. 6, pp. 1356–1364, May1996. The stabilization devices described in the Borst, et al. articleare marketed by Medtronic, Inc. and are known as “Octopus” devices.

It has been proposed to use such an Octopus device to retract the heartinto a desired position for surgery (and hold the retracted heart inthis position), as well as to stabilize a portion of the heart's surfacefollowing retraction (gross movement) of the heart. See, for example,PCT International Application WO97/10753 (by Medtronic, Inc.) entitled“Method and Apparatus for Temporarily Immobilizing a Local Area ofTissue,” published Mar. 27, 1997, especially with reference to FIG. 33thereof. However, no conventional Octopus device can support a beatingheart with adequate compliance to allow normal heart beating movement,and instead each conventional Octopus device would exert compressive ortwisting force on at least one side of the beating heart, therebyconstraining cardiac contraction and expansion. Also, one of thesmall-diameter suction small to reliably grip (and support) the heartwithout causing trauma to the heart surface. Thus, in order to reliably(but atraumatically) retract and support the heart in the retractedposition, many small-diameter suction cups (supported on a rigid framewhich frame is itself rigidly supported) need to exert suctionsimultaneously on the heart, which exacerbates the problem ofconstrained cardiac contraction and expansion due to the exertion ofcompressive or twisting force on the heart.

The apparatus of the invention differs in purpose and form fromconventional tissue stabilization devices. The purpose of the inventiveapparatus is to move an organ grossly from one position to another andmaintain the organ in the final position (without significantlyconstraining cardiac contraction and expansion). The inventive apparatusis not designed to stabilize specific areas of the organ. The shape andnature of the suction cup (or other suction member) of the inventiveapparatus differ from the suction cups of conventional tissuestabilization devices in the need to accommodate different anatomy. Forexample, the inventive suction member can be larger than a conventionaltissue stabilization device. Also, since the inventive apparatus exertssuction over a larger surface area of organ tissue, the requiredpressure differential can be less than that required by conventionaltissue stabilization devices. The low-pressure differential has aclinical benefit in that the potential for creation of hematomas islessened.

U.S. Pat. No. 5,799,661, issued Sep. 1, 1998 to Boyd, et al. (andassigned to Heartport, Inc.) describes (with reference to FIGS. 33A–33C)a suction cup manipulator on a long shaft. The suction cup is to beattached to an arrested heart by suction, and the device is thenmanipulated to move the heart around in the chest cavity. A vacuum isapplied to the cup to provide suction, and the vacuum is said preferablyto have a value not less than −150 mmHg (to avoid tissue damage). Thesuction cup is made of a soft, flexible elastomeric material such assilicone rubber, has a diameter of approximately 12 mm to 50 mm, and hasa textured, high friction distal surface (for gripping the heart). Thehigh friction can be achieved by a pattern of bumps or an absorbent highfriction material (such a nonwoven polyester fabric). A disadvantage ofthe bumps is that thy would likely cause trauma to the organ beingmanipulated (even with a vacuum in the preferred range).

U.S. Pat. No. 5,799,661 suggests without explanation that the suctioncup is flexibly mounted to the distal end of a rigid shaft, but it isapparent from FIGS. 33A–33B that this simply means that the cup itselfhas some flexibility so that the cup can bend relative to the rigidshaft. U.S. Pat. No. 5,799,661 does not teach attaching the suction cupto the shaft by a joint which provides limited freedom to translatealong a first axis and/or full (or at least limited) freedom to rotateabout the first axis, but no significant freedom to translate indirections perpendicular to the first axis. Thus, the suction cupapparatus described in U.S. Pat. No. 5,799,611 is useful only to retractan arrested heart; not a beating heart or other moving organ since thesuction cup apparatus of U.S. Pat. No. 5,799,611 does not havecompliance to allow for normal organ movement such as a heart beat, andwould instead exert compressive or twisting force on at least one sideof the moving organ, thereby constraining cardiac contraction andexpansion or other normal organ movement.

U.S. Pat. No. 5,782,746, issued Jul. 21, 1998, discloses an annularsuction device for immobilizing part of the surface of a heart duringsurgery. Although the device is said to allow the heart to beat in a“relatively normal” manner during surgery, the device is rigidly mountedto a fixed mounting structure during surgery, and thus neither thedevice nor the part of the heart surface which it immobilizes would havefreedom to move significantly relative to the mounting structure duringsurgery. The reference suggests positioning the device on the heart,applying vacuum to the device to cause it to exert suction on the heart,then moving the device to “partially” raise the heart, and then rigidlymounting the device to the fixed mounting structure so that the devicesupports the “partially raised” heart during surgery.

A key difference between the inventive apparatus and both conventionalapparatus for tissue stabilization and conventional apparatus for organretraction is that the inventive apparatus provides system compliancethat allows the target organ to maintain normal motion (e.g., normalcompression and expansion in the case that the organ is a beatingheart). In the case of a beating heart, this compliance providesdistinct clinical value by lessening the negative impact of manipulationon hemodynamics.

SUMMARY OF THE INVENTION

In a class of embodiments, the invention is an organ manipulatorincluding at least one suction member (e.g., a suction cup) andpreferably also a compliant joint to which the suction member ismounted. The compliant joint provides built-in system compliance so thatwhen the suction member supports an organ (e.g., a beating heart) bysuction, the suction member does not constrain normal motion of theorgan (e.g., normal beating motion of the heart), either during grossmovement of the organ into a retracted position or during surgery withthe organ attached to or held by the suction member in the retractedposition. In preferred embodiments the suction member is shaped andconfigured to retract a beating heart and suspend it in the retractedposition during surgery. As the suspended heart beats, the compliantjoint allows the heart to expand and contract freely (and otherwise movenaturally) so that hemodynamic function is not compromised. Suspensionof the beating heart below the suction member tends to expand the heartchambers, which in turn tends to reduce the amount of compressivedeformation of the heart and great vessels which would otherwise resultfrom pressing the heart with a stabilization device (such asstabilization feet) during surgery, so that the invention assists inoxygenation during surgery.

The suction member conforms (or, in some embodiments can be deformed toconform) to the anatomy of the organ. Preferably, its inner surface issmooth, concave, and lined with absorbent material to improve tractionwithout causing trauma to the organ (e.g., bruising) during retractionfrom one position to another within the body cavity. Preferably, thesuction member is a suction cup having a foam seal mounted around thecup's periphery.

Coupling a vacuum source to the suction member (with the member appliedto the organ surface) creates a differential in pressure between theinner and outer surfaces of the member. The pressure differential forcesthe suction member and organ surface together in such a manner as tocreate traction between the two. As a result of the traction, thesurface of the organ will move with the suction member. The device holdsthe organ with sufficient force to allow retraction using suction, andto maintain the organ in the desired position (i.e., by suspending itfrom the suction member) during surgery.

In preferred embodiments, the compliant joint couples the suction memberto an arm (which is rigid or can be placed in a rigid state), and thearm is adjustably mounted to a fixed mounting structure. The mountingstructure can be a conventional sternal retractor (of the type used tomaintain a sternal incision in an open state for cardiac access), anoperating table, or another rigid structure. When the organ is attachedto or held by (e.g., suspended below) the suction member, the compliantjoint gives the suction member freedom to move (at least axially alongthe axis of the suction member, e.g., vertically when the suction memberhas a vertical axis) relative to the arm and mounting structure inresponse to normal organ movement (e.g., beating of a heart) to avoidcompromising the normal functioning of the organ. When a beating heartis suspended below the suction member, the compliant joint allows theheart to expand and contract freely (at least vertically) as it beatsoptionally, the compliant joint also gives the organ freedom to rotateabout the axis of the suction member (typically, a vertical axis) and/orto swing relative to the arm.

In preferred embodiments, the inventive apparatus provides for compliantretraction of a beating heart (or other organ) in the sense that itretracts the organ via suction, while allowing normal myocardialmovement (or other normal organ movement) in at least the verticaldirection, and optionally also allowing normal organ movementperpendicular to the vertical direction (e.g., pivoting or twistingmotion about a vertical axis). In some such preferred embodiments, thecompliant joint is a sliding ball joint attached to a movable arm, andthe arm can be locked in any of a variety of positions (relative to afixed supporting structure) to allow adjustable degrees of organretraction. The compliance provided by the ball joint allows the organto better tolerate manipulation.

Preferably, the suction member is specially designed to decrease traumato the heart muscle (or other organ tissue) during attachment, and theapparatus is preferably implemented to have one or more of the followingfeatures: an absorbent cup lining for increased holding power, a smoothand soft inner cup surface to decrease myocardial bruising (hematomaformation) and to diffuse the suction across the cup, a means forregulation of suction intensity, and a vacuum accumulator in the suctionline to decrease immediate loss of holding power with variations invacuum supply.

In other embodiments, the inventive apparatus includes multiple suctionmembers (e.g., multiple suction cups) mounted on the ends of retractingfingers for gripping an organ, with the fingers implementing a compliantjoint. In other alternative embodiments, the inventive apparatusincludes a bio-absorbable disc with an adhesive surface to be adhered tothe heart or other organ (instead of a suction member), with the discpreferably being mounted to a compliant joint.

In other embodiments, the invention is a method for compliant retractionof an organ, including the steps of retracting the organ using suction,and supporting the organ in the retracted position using suction, insuch a manner that the organ has freedom to move normally (e.g., to beator undergo other limited-amplitude motion) at least in the direction inwhich the suction is exerted during both steps. In some suchembodiments, the method includes the steps of retracting the organ usingsuction, and suspending the organ in the retracted position usingsuction, in such a manner that the organ has freedom to move normally(e.g., to beat or undergo other limited-amplitude motion) in at leastthe vertical direction during both steps. One embodiment is a method forretracting a beating heart, including the steps of affixing a suctionmember (e.g., a suction cup) to the heart at a position concentric withthe apex of the heart (preferably the suction member has sufficientcurvature to conform with the apex and is shaped to be at leastgenerally symmetric with the apex) and applying suction to the heart(e.g., by coupling the suction member to a vacuum source), and movingthe suction member to retract the heart to a desired position forsurgery such that the heart has freedom to undergo normal beating motion(at least along the axis of the suction member) during retraction.Preferably, the suction member is mounted to a fixed assembly (e.g., afixedly mounted sternal retractor) by a compliant joint in such a mannerthat the suction member does not constrain normal beating motion of theheart, either during gross movement of the member (with heart) into thedesired position or while the heart is supported by (e.g., suspendedvertically below) the member during surgery in such position. In suchpreferred embodiments, as the heart beats, it is free to expand andcontract normally (with the compliant joint allowing the suction memberto oscillate along the axis of the suction member, and optionally alsoto twist about such axis) so that hemodynamic function is notcompromised.

Other aspects of the invention are a flexible locking attachment arm(having both a flexible state and a rigid state) to which the inventivesuction member (or compliant joint) is mounted, and an organ manipulatorincluding such a locking arm and at least one suction member (orcompliant joint and suction member) mounted to the arm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the inventiveorgan manipulation apparatus.

FIG. 2 is a perspective view of another preferred embodiment of theinventive organ manipulation apparatus.

FIG. 3 is a perspective view of another preferred embodiment of suctioncup 1A of FIG. 2.

FIG. 4 is a cross-sectional view of the FIG. 3 embodiment of cup 1A.

FIG. 5 is a perspective view of a portion of another preferredembodiment of the inventive organ manipulation apparatus.

FIG. 6 is a more detailed perspective view (partially cut away to showelement 29) of a portion of the FIG. 5 embodiment.

FIG. 7 is a perspective view of a portion of an alternative embodimentof the inventive organ manipulation apparatus.

FIG. 8 is a side cross-sectional view of another preferred embodiment ofthe inventive suction cup.

FIG. 9 is a perspective view of a portion of another alternativeembodiment of the inventive organ manipulation apparatus.

FIG. 10 is a perspective view of a portion of a variation on the FIG. 9embodiment.

FIG. 11 is a perspective view of a portion of another preferredembodiment of the inventive organ manipulation apparatus.

FIG. 12 is a more detailed perspective view (partially cut away to showelement 55A) of a portion of the FIG. 11 embodiment.

FIG. 13 is a perspective view of a portion of another alternativeembodiment of the inventive organ manipulation apparatus.

FIG. 14 is a perspective view of a portion of another alternativeembodiment of the inventive organ manipulation apparatus, which employshinged fingers and multiple suction cups.

FIG. 15 is a perspective view of one finger 72 of the FIG. 14 apparatusgripping the surface of heart 9, and shows (in phantom view) theposition the finger would have if the heart surface were in a lowerposition.

FIG. 16 is an end view of a portion of one embodiment of the inventivesuction cup.

FIG. 17 is a cross-sectional view of the cup portion of FIG. 16, alongline 17—17 of FIG. 16.

FIG. 18 is an end view of a seal for use with the cup portion of FIGS.16 and 17.

FIG. 19 is a side view of the seal of FIG. 18.

FIG. 20 is a perspective view of the suction cup and compliant joint ofanother alternative embodiment of the inventive apparatus.

FIG. 21 is a top view of arm 93 (with pins 96) of FIG. 20.

FIG. 22 is a side elevational view of the suction cup and compliantjoint of another alternative embodiment of the inventive apparatus.

FIG. 23 is an end view of a portion of another embodiment of theinventive suction cup.

FIG. 24 is a cross-sectional view of the cup portion of FIG. 23, alongline 24—24 of FIG. 23.

FIG. 25 is an enlarged view of a portion of the cup structure shown inFIG. 24, with gauze and a foam seal positioned in the cup.

FIG. 26 is a side cross-sectional view of another embodiment of theinventive suction cup, including gauze and a foam seal positioned in thecup.

FIG. 27 is a perspective view of a portion of an alternative embodimentof the inventive organ manipulation apparatus.

FIG. 28 is a perspective view of another embodiment of the inventivesuction member.

FIG. 29 is a perspective view of another embodiment of the inventivesuction member.

FIG. 30 is a perspective view of another embodiment of the inventivesuction member, with a compliant joint for mounting it to a rigidstructure.

FIG. 31 is a side cross-sectional view of another embodiment of theinventive suction member.

FIG. 32 is a side elevational view of a preferred flexible lockingattachment arm for use in supporting the suction member and compliantjoint of the invention.

FIG. 33 is a side cross-sectional view of one ball joint of the arm ofFIG. 32.

FIG. 34 is a side cross-sectional view of a ball joint of anotherembodiment of a flexible locking attachment arm for use in supportingthe suction member and compliant joint of the invention.

FIG. 35 is a top elevational view of a sleeve of another embodiment of aflexible locking attachment arm for use in supporting the suction memberand compliant joint of the invention.

FIG. 36 is a cross-sectional view of the sleeve of FIG. 35, taken alongline 36—36 of FIG. 35.

FIG. 37 is a side elevational view of a ball joint for use with thesleeve of FIG. 35 in a flexible locking attachment arm.

FIG. 38 is a side elevational view of a portion of a flexible lockingattachment arm including alternating ball joints (of the type shown inFIG. 37) and sleeves (of the type shown in FIG. 35).

FIG. 39 is a perspective view of a portion of a variation on the FIG. 1apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout this disclosure, including in the claims, the expression“compliant joint” is used in a broad sense to denote any mechanicalcoupling capable of bearing the load of the inventive suction member(and the organ attached by suction to the suction member) while allowingthe suction member (and organ) freedom to move in the described manner.The compliant joint can be implemented in any of a wide variety of ways,including (but not limited to) a sliding ball joint, a hinged joint, apin which slides in a slot, a universal joint, or a spring assembly inwhich the spring constant is determined by a bellows, piston, metalspring, or some other compliant element).

A first preferred embodiment of the invention will be described withreference to FIG. 1.

The FIG. 1 embodiment is designed to retract heart 9 (by exertingsuction) to a position suitable for performing surgery thereon, and toretain heart 9 in the retracted position (by continued exertion ofsuction thereon) with limited freedom to move. In the FIG. 1 embodiment,the inventive apparatus includes the following main elements: suctioncup 1 (including conforming seal 2 which extends around the periphery ofcup 1), ball sliding joint assembly 3, flexible locking attachment arm 4(which has both a rigid and a flexible state), suction line 5, suctionflow regulator 6, and vacuum accumulator 7.

We will denote the surface of the inventive suction cup (e.g., cup 1 ofFIG. 1 or cup 1A of FIG. 2) which contacts the organ to be retracted asthe “inner” surface of the suction cup.

Preferably, the inner surface of suction cup 1 is concave, and is shaped(or can be shaped) so that cup 1 can be attached directly to the apex ofheart 9 as shown with seal 2 conforming to the heart surface at theapex, so that cup 1 can lift the heart by exerting suction thereon. Insome preferred embodiments cup 1 is not flexible (except for seal 2),but in other preferred embodiments it is flexible. In some preferredembodiments, cup 1 is implemented to be flexible but to have a shapememory, such as by forming the cup of metal mesh (which can resemblechicken wire) coated with a continuous sheet of silicone rubber (andthen attaching seal 2 around its periphery). In embodiments having ashape memory, the user can deform the cup (e.g., by pressing it with hisor her fingers) to conform the cup to fit against any of a variety ofdifferent portions of an organ (or against any of a variety of differentorgans) and the cup will remain in the selected shape until laterdeformed by the user.

In all embodiments, conforming seal 2 forms a seal with heart 9 (oranother organ) while also preventing the organ tissue from being suckedsubstantially into the internal area of the cup. Conforming seal 2 ispreferably made of biocompatible foam that is glued to the remainingportion of cup 1. In a class of preferred embodiments, seal 2 isidentical to seal 35 of cup 1A (to be described below with reference toFIGS. 2, 3, and 4).

With reference to FIG. 1, the body of suction cup 1 is preferably madeof flexible material (e.g., elastomeric material having no shape memory,or a continuous sheet of elastomeric material coated over a deformablemetal mesh which has a shape memory), and its inner surface ispreferably lined with a soft and absorbent material (not shown in FIG.1). The absorbent lining can be a biocompatible fabric (preferablynon-woven rayon/viscose fabric), gauze, or material of the typecurrently used in neuro-sponges, and is capable of absorbing enoughblood and/or other bodily fluid to significantly improve tractionbetween the cup and the organ. The absorbent lining also functions todiffuse the suction.

In alternative embodiments, the inner surface of cup 1 is implementedwith compliant cleats protruding out therefrom, or is otherwise texturedso as to assist in providing grip on the organ tissue.

In any embodiment of the invention, the inner surface of the suction cup(e.g., cup 1) is gas-permeable (e.g., porous, or having at least oneorifice extending through it). The pores are (or the orifice is) influid communication with a vacuum source. Thus, when the vacuum sourceis active a large surface area of the organ is sucked by the vacuumagainst the cup's inner surface, with a suction force sufficient toovercome gravity to allow the organ to be moved grossly to a desiredposition by moving the suction cup (or an element to which the suctioncup is mounted).

Suction is provided to suction cup 1 by means of flexible suction line5. The distal end of line 5 is in fluid communication with the pores (ororifice) through the inner surface of cup 1, and the proximal end ofline 5 is in fluid communication with suction flow regulator 6. Thesuction flow rate is controlled by flow regulator 6. Vacuum accumulator7 is coupled to flow regulator 6, and serves as a low-pressure reservoirhaving sufficient volume that it can provide suction in the event of aninterruption of regular suction flow from a vacuum source (not shown,but which can be a wall source).

In preferred implementations for use in retracting a human heart,suction cup 1 has a diameter (at its outer periphery) greater than aboutone inch (25.4 mm), and the vacuum provided by the vacuum source is inthe range from −7 psi to −5 psi (−362 mmHg to −258 mmHg). For aparticular application, the vacuum provided by the vacuum source shouldbe determined (e.g., experimentally) to be as close as possible toatmospheric pressure while still providing enough suction force toreliably grip the organ to be retracted.

Ball sliding joint 3 (which includes ball 3A and U-shaped element 3C)connects suction cup 1 to flexible locking attachment arm 4. As shown inFIG. 1, one end of flexible locking attaching arm 4 is attached tosternal retractor 8 (this end can alternatively be attached directly toan operating table) and the other end of arm 4 is attached to ballsliding joint 3. Ball 3A rides in grooves 3B of element 3C. Cup 1 ismounted rotatably to element 3C (e.g., by a binding screw which couplesthem together), so that when element 3C is oriented with grooves 3Bvertical (as shown in FIG. 1), cup 1 can rotate freely about a verticalaxis relative to element 3C. Thus, joint 3 allows cup 1 (and heart 9) torotate about a vertical axis relative to arm 4 and retractor 8 (as ball3A rotates relative to element 3C). Joint 3 also allows cup 1 (and heart9) limited freedom to translate up and down (along the centrallongitudinal axis L of cup 1, which is oriented vertically in FIG. 1)relative to retractor 8 (as vertical grooves 3B slide up and downrelative to ball 3A) thereby providing compliance to the system. Asheart 9 beats, its outer surface expands and contracts (which causes cup1 and element 3C to oscillate vertically relative to stationary ball 3A)and its apex may twist about a vertical axis relative to ball 3A and arm4.

The FIG. 1 apparatus can be oriented so that arm 4 does not extend in ahorizontal plane (relative to the earth). Regardless of the orientationof arm 4, when cup 1 supports an organ, element 3C will rotate relativeto ball 3A until grooves 3B are vertical.

Flexible locking attachment arm 4 is designed to have both a flexiblestate and a rigid state. In a preferred implementation, this is achievedby implementing free portion 4B of arm 4 (in a conventional manner) toinclude a cable running from mount 4A through a series of ball joints 4C(or alternating ball joints and sleeves), so that portion 4B can bechanged between a flexible state and a rigid state by tightening (oruntightening) the cable using a knob mechanism with a clutch. The clutchguards against overtightening of the assembly, and provides tactilefeedback when the maximum tightening is achieved. Preferredimplementations of ball joints (or ball joints and sleeve) for use inarm 4 will be described below, with references to FIGS. 32–38.

The pressure at the inner surface of cup 1 is reduced by opening suctionflow regulator 6, thus enabling cup 1 to provide suction. In operation,cup 1 is placed against the appropriate portion of heart 9 (for example,on the heart's apex as shown in FIG. 1) either before or after flowregulator 6 is opened, depending on the particular application. When cup1 is positioned against and providing suction to organ 9, flexiblelocking attachment arm 4 is manipulated to retract the organ (with cup 1and ball sliding joint 3) into a desired position. Specifically,flexible locking attachment arm 4 is moved (e.g., by translating mountportion 4A along member 8, and/or placing free portion 4B in a flexiblestate and bending free portion 4B) to manipulate organ 9 into thedesired position. Ball sliding joint 3 permits cup 1 to pivot relativeto free portion 4B of arm 4 (and ball 3A to translate along grooves 3B)while the organ is manipulated. When the organ is properly positioned,portion 4A of arm 4 is locked to retractor 8 and portion 4B of arm 4 islocked into its fixed state, but ball sliding joint 3 is stillconfigured to provide compliance.

An alternative embodiment of the invention will next be described withreference to FIG. 2. Elements 3, 5, 6, 7, and 8 of the FIG. 2 embodimentare identical to the identically numbered elements of theabove-described FIG. 1 embodiment (and the description thereof will notbe repeated). Suction cup 1A of FIG. 2 differs slightly from cup 1 ofFIG. 1, in that suction line 5 is coupled (through ball 3A and element3C) to a gas-permeable portion (an orifice or pores) at the center ofcup 1A, whereas suction line 5 is coupled to a gas-permeable portion(orifice or pores) of cup 1 at a location away from the center of cup 1.

In the FIG. 2 embodiment, rigid arm 10 (which replaces flexible lockingarm 4 of FIG. 1) exerts a retracting force upon suction cup 1A. Rigidarm 10 is preferably adjustably mounted to retractor 8 by a standardtool holder 11 (of a type commonly used in the practice of surgery).Rigid arm 10 is hollow, and suction line 5 is routed through rigid arm10 (and then through ball 3A and element 3C) to cup 1.

A preferred embodiment of cup 1A is shown in more detail in FIGS. 3 and4. In this embodiment, cup 1A has a flexible silicone rubber shell 31with a generally cylindrical attachment portion 32 that defines acentral orifice through the shell. Portion 32 is shaped for attachmentto the distal end of line 5. The outer periphery of shell 31 is a mildellipse (the ratio of its long axis to and short axis is less than two,e.g., the ratio is about 1.45). Absorbent material 33 (e.g., gauze or“bleed” cloth) is loosely packed against shell 31 to absorb blood andother fluid that may be present at the organ surface in order to improvethe grip of cup 1A on the organ. Non-abrasive, organ-contacting (e.g.,myocardium-contacting) mesh 34 is installed over material 33 to retainthe material 33 in the position shown.

Tapered conformal seal 35 (preferably made of biocompatible foam) isglued to the portion of mesh 34 in contact with shell 31 (and to theperipheral portion of shell 31 itself). Specifically, glue 36 is placedon mesh 34 near the periphery of shell 31 (and on shell 31 around itsperiphery), and foam seal 35 is positioned over glue 36 to glue togetherthe seal 35, mesh 34, and shell 31 as shown. Glue 36 should not extendinward to (or beyond) the inner edge of seal 35, so as to avoidintroducing a stiff (hardened glue) surface that would contact the organduring exertion of suction on the organ.

In alternative embodiments of the invention, compliant joint 3 (of FIGS.1 and 2) is replaced by another type of compliant joint, such as oneincluding a pin which slides in a slot, a bellows, a piston, a spring,or some other compliant element. In one such alternative embodiment(shown in FIG. 5), rigid arm 24 replaces arm 10 (of FIG. 2). Theproximal end of arm 24 is attached to sliding mount 28. A second slidingmount 26 attached to arm 24 can be translated to a desired locationalong arm 24 and then locked into place. Suction cup 21 is attached tothe distal end of rigid tube 22 (preferably in such a manner that cup 21has freedom to rotate about the axis of tube 22), and the distal end ofcompliant element 27 is attached to the proximal end of tube 22. Suctionline 25 is attached to element 27 in such a manner that line 25 is influid communication with the interior of tube 22, so that a vacuumsource can evacuate line 25 and tube 22 and cause cup 21 to exertsuction on organ 9 (a human heart) when cup 21 is positioned as shownagainst heart 9. The proximal end of element 27 is attached to slidingmount 26 (so that element 27 and tube 22 have freedom to pivot togetheras a unit relative to mount 26).

To position mount 26 in the desired position, mount 28 is translatedalong a sternal retractor (or operating table) until it is locked at anappropriate position, and mount 26 is loosened (relative to arm 24) sothat it is free to slide along arm 24 into the desired position (therebycausing the assembly to retract heart 9 coupled to cup 21 into a desiredposition for surgery). In its desired position, mount 26 is tightenedagainst arm 24 so that it thereafter remains fixed in the desiredposition along arm 24. Compliant element 27 includes a piston and allowstube 22 limited freedom to translate (parallel to the common axis oftube 22 and element 27) relative to arm 24, for example to accommodatemotion of heart 9 as it beats during surgery. Alternatively, compliantelement 27 is replaced by a spring, bellows, or other compliant elementor assembly, which allows tube 22 such limited freedom to translaterelative to arm 24. In the preferred embodiment shown in FIG. 6, element27 is a tube having closed end 28, with slidable piston 29 mounted inthe tube to seal the tube's other end (except that piston 29 allows airto flow from cup 21's inner surface through tube 22, piston 29, andelement 27 into suction line 25). A vacuum source draws air through line25, thus evacuating the space within element 27 between end 28 andpiston 29 (except for air flowing at a low flow rate from cup 21 throughtube 22 into this space). As heart 9 beats, it periodically pulls cup21, tube 22, and piston 29 together as a unit away from end 28 ofelement 27, and then relaxes to allow the vacuum source to pull piston29 back toward end 28.

The traction on heart 9 is automatic when the vacuum is engaged and cup21 is attached to the heart. The traction and suction cup forces willremain in a fixed ratio to each other regardless of the strength of thevacuum. The ratio is determined by the area of cup 21 (over which cup 21exerts suction) and the area of piston 29. This parameter should becontrolled to ensure that the suction force is only as strong aswarranted to retract the heart, in order to avoid trauma to the surfaceof the heart undergoing suction by the inventive apparatus. The tractionforce should never be strong enough to pull cup 21 off the heart (atleast directly). With a vacuum accumulator of sufficient size (e.g.,accumulator 7 of FIG. 1), it can be assured that the heart is returnedgently to its non-retracted position even if the vacuum source issuddenly decoupled from the inventive apparatus.

In a variation on the FIG. 5 embodiment, straight rod 24 is replaced bya curved rod (whose curvature is sufficiently limited to allow mount 26to slide along it).

Another variation on the FIG. 5 embodiment will be described withreference to FIGS. 11 and 12. In the embodiment of FIGS. 11 and 12,straight rod 24 is replaced by rigid member 54 (which is fixedlyattached to mount 28), long, threaded bolt 55 having one end mounted tomember 54 (with freedom to rotate but not translate relative to member54), and crank 57 attached to the other end of bolt 55. Bolt 55 can berotated relative to member 54 by turning crank 57 (with non-threadedportion 55A of bolt 55 rotating in a non-threaded orifice in member 54).Mount 26 (of FIG. 5) is replaced by threaded mounting member 56 whosethreads mate with those of bolt 55. Thus, threaded mounting member 56can be advanced along bolt 55 (together with compliant element 27 andsuction cup 21 attached to member 56) by turning crank 57.

In another alternative embodiment of the invention shown in FIG. 7,suction cup 41 is attached by cable 42 to hollow, flexible lockingattachment arm 46 (which has both a flexible state and a rigid state).The other end of cable 42 is attached to rod 48 of a piston (not shown)within compliant element 49. Mount 43 is slidably mounted relative tosternal retractor 8, arm 46 is rotatably mounted to mount 43, andchamber 49 is fixedly mounted to mount 43. After mount 43 has been movedinto a desired position relative to sternal retractor 8, it can belocked to mount 43. Arm 46 can be rotated relative to mount 43 andlocked into a desired rotational position relative to mount 43. Arm 46(like arm 4 of FIG. 1) can also be moved relative to sternal retractor 8(when in its flexible state) and then locked into a desired position byplacing it in its rigid state. Thus, cup 41 can be positioned as desiredrelative to retractor 8. The FIG. 7 apparatus provides cup 41 freedom toswing (on cable 42) relative to arm 46 and it provides cup 41 limitedfreedom to move vertically relative to retractor 8.

Compliant element 49 includes a piston (not shown) which is coupled torod 48 to allow rod 48 limited freedom to translate (parallel to thecommon axis of rod 48 and element 49) relative to mount 43, for exampleto accommodate motion of a heart (supported by cup 41) as the heartbeats during surgery. In a preferred implementation, element 49 enclosesa volume between closed end 49A and a slidable piston. The piston isfixedly attached to rod 48. Suction line 50 is connected to element 49(in fluid communication with the volume enclosed by element 49) so thata vacuum source can draw air through line 50 from such enclosed volume.The same vacuum source is coupled to suction cup 41 via suction line 45.Lines 45 and 50 are both coupled by line 51 to the vacuum source. As aheart (supported by suction cup 41) beats, it periodically pulls cup 41,cable 42, rod 48, and the piston together as a unit away from end 49A ofelement 49, and then relaxes to allow the vacuum source to pull thesecomponents back toward end 49A. Preferably, the inner surface of arm 46is lined with Teflon material or the like (or includes bearings made ofsuch material) to reduce friction on cable 42.

In the FIG. 7 embodiment, suction cup 41 can be implemented to be rigid(e.g., it is composed of Delrin, ABS, Ultem, or polycarbonate plastic,or other hard plastic, with its inner surface lined with absorbentmaterial), and has seal 41A attached (e.g., by glue, which can beSilastic Medical Adhesive Silicone Type A, available from Dow Corning,when the cup is made of Delrin plastic) around its periphery. Seal 41Acan be a biocompatible foam seal as in cup 1A of FIGS. 3 and 4). Cup 41has a shape which conforms to a target portion of a typical organ of thetype to be retracted using the cup, and its inner (concave) surface ispreferably smooth and lined with absorbent material to improve traction.

Adhesives suitable for use with plastic or silicone components ofvarious embodiments of the invention include Silastic Medical Adhesive(available from Dow Corning), and Loctite 4541 or Loctite 4011 adhesive.

In a class of preferred embodiments, the suction cup of the invention isimplemented to be flexible but to have a shape memory. One suchembodiment will next be described with reference to FIG. 8. Suction cup1B of FIG. 8 is made of metal mesh 40 (which can resemble chicken wire)coated on both sides with a continuous sheet 39 of flexible siliconerubber (or other flexible, biocompatible material). Thus, the organ tobe manipulated does not contact metal mesh 40, and instead the innersurface of the cup is a smooth sheet of silicone rubber.

Generally cylindrical attachment portion 38 defines a central orificethrough the otherwise continuous sheet 39. Portion 38 is shaped forattachment to the distal end of a suction line. Tapered conformal seal35 (preferably made of biocompatible foam) is glued to the peripheralportion of sheet 39.

In use, cup 1B of FIG. 8 is placed over the organ (with seal 35 againstthe organ surface) and mesh 40 is deformed (by the user's fingers) toconform with the organ surface. Mesh 40 will retain the cup in its finalshape after the user has finished shaping the cup. Then, a vacuum sourceis coupled to the cup to draw air through the orifice through attachmentportion 38. This evacuates the region bounded by the cup's innersurface, seal 35, and the organ, and causes cup 1B to exert suction onthe organ.

In another class of preferred embodiments, the inventive suction cup isimplemented to be rigid (e.g., it is composed of hard plastic with itsinner surface lined with absorbent material), and has a seal around itsperiphery (e.g., a biocompatible foam seal). The cup has a shape whichconforms to a target portion of a typical organ of the type to beretracted using the cup. The inner surface of the cup is preferablysmooth, and lined with absorbent material to improve traction. Anexample of such a rigid cup is cup 41 of FIG. 7.

Another example is a suction cup assembled by gluing seal 82 (of FIGS.18 and 19) to cup portion 81 (of FIGS. 16 and 17). In the embodiment ofFIGS. 16–19, cup portion 81 is machined from rigid Delrin plastic, andseal 82 is made of biocompatible foam. The end surface of cup portion 81has a central orifice 83 extending therethrough. To assemble the cup,tapered surface 85 of seal 82 is glued to tapered inner surface 84 ofportion 81 at the periphery of portion 81 (e.g., with Silastic MedicalAdhesive Silicone Type A, available from Dow Corning). To attach the cupto a vacuum source, a threaded pipe-shaped member is attached (e.g.,using nuts and a washer) to the end surface of portion 81 (so as toextend through orifice 83), and a suction tube is then placed throughthe pipe-shaped member into fluid communication with inner surface 84 ofportion 81. To attach the cup to a compliant joint (which is adjustablyattached to a fixed structure), the pipe-shaped member can be screwedonto a threaded portion of the joint (or the pipe-shaped member can beotherwise attached to the joint). Steel wool (or another substance) canbe packed loosely in the cylindrical bottom of portion 81 to preventloss of fluid communication between the cup's inner surface 84 and thesuction line, and the inner surface 84 of portion 81 can be lined withabsorbent material.

Another embodiment of the invention will be described with reference toFIG. 20. The embodiment of FIG. 20 includes suction cup 91 (which has acircular periphery and includes seal 92 which extends around cup 91'speriphery to provide a vacuum seal when the cup placed in contact withan organ), suction line 97 (which is coupled to a vacuum source toevacuate the volume inside cup 91 when the cup is positioned in contactwith an organ), and a compliant joint including element 94 (havingparallel slots 95 in opposing portions of its side wall) and arm 93having pins 96 which ride in slots 95. Both slots 95 (only one of whichis shown in FIG. 20) are oriented parallel to the central longitudinalaxis of cup 91. Pins 96 and the distal portion of arm 93 are bettershown in FIG. 21. With pins 96 riding in slots 95, arm 93 can supportelement 94, cup 91, and an organ suspended (by suction) from cup 91.Since element 94 can pivot (about pins 96) relative to arm 93, gravitywill ensure that slots 95 (and the central longitudinal axis of cup 91)will remain generally vertical during organ retraction (although theywill not necessarily remain fully vertical). Since slots 95 aresubstantially longer than the diameter of each pin 96, the assemblycomprising element 94 and cup 91 is free to slide vertically relative topins 96 during organ retraction. Thus, in response to beating of a heartsuspended from cup 91, the assembly comprising element 94 and cup 91 isfree to oscillate vertically relative to fixedly held pins 96 and arm93. Cup 91 is attached to element 94 (e.g., by a binding screw) in sucha manner that it can rotate freely relative to element 94. Typically,each slot 95 is sufficiently long to allow vertical oscillation of cup91 with an amplitude up to about 0.5 inch.

Another embodiment of the invention, to be described with reference toFIG. 22, is designed to minimize the overall vertical size of thesuction cup and compliant joint assembly. The FIG. 22 embodimentcomprises suction cup 101 (which has a circular periphery and a sealportion which extends around the periphery), suction line 107 (which iscoupled to a vacuum source to evacuate the volume inside cup 101 whenthe cup is positioned with the seal portion in contact with an organ),and a compliant joint (including elements 102, 103, and 104) forattaching rigid arm 104 to the rest of the FIG. 22 apparatus. Two pins105 are fixedly attached to cup 101 in the positions shown. Element 102has parallel slots 108 in its left and right side portions, and one ofthe pins 105 rides in each of the slots 108. Member 103 is rotatablyattached to element 102 (e.g., by a binding screw) in such a manner thatelement 102 is free to rotate about a vertical axis relative to member103. Member 103 is mounted to rod 104 with freedom for member 103 toswing about the axis of rod 104. With pins 105 riding in slots 108 ofmember 102, arm 104 supports element 102 and member 103, and element 102in turn supports cup 101 and an organ suspended (by suction) from cup101. Since member 103 can pivot about arm 104 and pins 105 can rotaterelative to the slots 108, gravity will ensure that the slots (and thecentral longitudinal axis of cup 101) will remain vertical during organretraction. Slots 108 should be substantially longer than the diameterof each pin 105, so that pins 105 and cup 101 are free to slidevertically relative to element 102 (and thus relative to arm 104) duringorgan retraction. Thus, in response to beating of a heart suspended fromcup 101, cup 101 is free to oscillate vertically relative to fixedlyheld arm 104.

Another example of the suction cup of the invention, designed to havelow profile, will be described with reference to FIGS. 23–25. As shownin FIGS. 23 and 24, the cup has a truncated conical profile, withannular end surface 112 (having central orifice 113 extendingtherethrough) at one end, and circular periphery 110 at the other end.Orifice 113 is for attaching the cup to a compliant joint. Suctionorifice 111 extends through the conical side wall of the cup (forconnecting a suction line to the cup), and gauze can be packed into thevolume surrounded by cylindrical surface 115 (FIG. 25 shows gauze 120 sopacked). Foam seal 121 (partially shown in FIG. 25) can be glued to flatannular surface 116 and the conical side wall portion between surface116 and periphery 110. The conical side wall is oriented at an angle of35 degrees with respect to the cup's central longitudinal axis L. In atypical implementation, the cup has a height of 0.95 inch (from end 112to the plane of periphery 110), the center of orifice is 0.56 inch fromthe plane of periphery 110, the diameter of cylindrical surface 115 is0.75 inch, and periphery 110 has a diameter of 1.95 inches. The cup ofFIGS. 23 and 24 can be machined from ABS material or rigid plastic(e.g., Delrin material).

In variations on the embodiment of FIGS. 23 and 24, the angle of theconical side wall (relative to the central longitudinal axis L) isvaried to vary the diameter of periphery 110. For example, this anglecan be 28 degrees (rather than 35 degrees as in FIG. 24) to giveperiphery 110 a diameter of 1.64 inches, or 21 degrees (rather than 35degrees) to give periphery 110 a diameter of 1.35 inches. Decreasing theangle between the conical side wall and the central longitudinal axis Ldecreases the diameter of periphery 110. We expect that the minimumuseful diameter of periphery 110 will typically be about 1.35 inches(where the cup is to be affixed to the apex of a heart), although it maybe as low as about 1 inch for some applications.

As shown in FIG. 25, when gauze 120 is packed into the volume surroundedby cylindrical surface 115 (of the cup of FIG. 24) and foam seal 121 ismounted in its proper position, there may be a gap between the seal andgauze at the right-angled intersection of surface 115 with surface 116.Under certain operating conditions, exposure of the heart tissue to suchgap (during application of suction to the heart) may result inirritation to the heart tissue and/or sucking of an excessive amount ofheart tissue into the cup. The FIG. 26 embodiment is designed to reduceor eliminate this potential problem. Note also that the bottom of thecup can be equipped with ribs (rib members) to prevent fabric and tissuefrom being sucked up into the suction tube orifice of the apparatus.

The FIG. 26 embodiment is shaped slightly differently than that of FIGS.23–25. More specifically, the FIG. 26 embodiment differs from that ofFIGS. 23–25 in that tapered (frusto-conical) surface 125 replacescylindrical surface 115 of FIGS. 24–25, and in that flat annular surface126 replaces surface 116. Components of the FIG. 26 embodiment that areidentical to those of FIGS. 23–25 are identically numbered in FIGS.23–26. Due to the geometry of the FIG. 26 embodiment, when gauze 120 ispacked into the volume surrounded by surface 125 and foam seal 121 ismounted in its proper position, there is a smooth, continuous transitionbetween the seal and gauze at the intersection of surface 125 withsurface 126.

For heart manipulation, the inventive cup preferably has a generallyhemispherical (or concave elliptical) shape with a circular (or mildelliptical) periphery, so that it conforms to the apex of the heart.Cups having less curvature (flatter cups) and/or rectangular peripheryhave been found to be less suitable for heart retraction since they mustbe affixed to relatively flatter surfaces of the heart (not to the apex)and have a greater tendency to decouple from the heart after beingaffixed. However, such alternative cup embodiments may be useful forretracting or otherwise manipulating organs other than the heart.

In a class of alternative embodiments, the inventive suction member iseffectively custom-fitted to the organ to be supported and manipulated.One way to accomplish such custom-fitting is to implement the suctionmember as a pellet-filled flexible body which is impervious to fluidflow (except in that it has a gas permeable inner surface which allows avacuum source to pull a vacuum on a portion of an organ facing thesuction member). An example of such a suction member is a beanbag-likebody comprising a flexible plastic enclosure filled with small pellets(which can be beads). In use, the body is placed against the appropriatepart of organ and air (or other gas) within the body is then evacuatedso that the pellets remaining in the evacuated body form a rigidstructure which conforms to the relevant surface of the organ. Since theinner surface (which contacts the organ) of the pellet-filled body ispermeable to gas, the vacuum source causes the member to exert a suctionforce on the organ while also maintaining the member in its rigid state.

With reference to FIG. 9, we describe in greater detail such a suctionmember which comprises a rigidizing bag containing pellets (which can bebeads). In the FIG. 9 embodiment, the suction member compriseselastomeric beads 12 (which can be injection molding stock) contained inrigidizing bag 11. One face of bag 11 is attached by a compliant joint13 to the distal end of rigid tube 14 (with an orifice in such face ofthe bag in fluid communication with the tube's interior). The proximalend of tube 14 is coupled to a vacuum source so that pulling a vacuum ontube 14 evacuates bag 11 thereby rigidizing it. The inner surface of bag11 is permeable to gas (e.g., it is porous or has at least one smallorifice extending through it) so that the vacuum source will also causethe suction member to exert suction on an organ in contact with themember's inner surface.

In a variation on the FIG. 9 embodiment, only the perimeter of thesuction member is rigidizible (to conform with an organ surface againstwhich the member is placed). The member's central portion is rigid. Forexample, as shown in FIG. 10, the suction member comprises a rigidcentral portion 18 (having concave inner surface, and preferably made ofhard plastic lined with soft absorbent fabric or other absorbentmaterial) and a rigidizing bag 19 (containing elastomeric beads) whichextends around the periphery of central portion 18. Compliant joint 13is coupled between the distal end of rigid tube 14 and central portion18. The interior of tube 14 is in fluid communication with the interiorof bag 19, so that pulling a vacuum on tube 14 evacuates bag 19 therebyrigidizing it. The inner surface of portion 18 (or bag 19) is permeableto gas (e.g., it is porous or has at least one small orifice extendingthrough it to tube 14) so that the vacuum source will also cause thesuction member to exert suction on an organ in contact with the member'sinner surface.

In preferred embodiments (including the FIG. 1 and FIG. 2 embodiments),the suction member of the inventive apparatus is implemented with asmooth inner surface (e.g., a smooth biocompatible foam seal around theperiphery and a smooth fabric surface between the center and periphery)to provide traction (e.g., by absorbing blood which would otherwisecause the member to slip from the organ) while avoiding trauma to theorgan (e.g., bruising) during retraction. For many surgicalapplications, it is important to implement the suction member with sucha smooth inner surface. Alternatively, in some surgical applications inwhich the organ to be manipulated is not highly vulnerable to trauma, itmay be desirable for the inner surface of the suction member to besomewhat rough (e.g., with bumps or the like protruding therefrom) ortextured to improve traction between the suction member and organ.

The suction member of the invention (e.g., suction cup 61 shown in FIG.13) can be made of flexible plastic film (e.g., film 62 of cup 61) withits inner surface lined with absorbent material (e.g., felt or felt-likematerial), and with a hyper-extensible elastomeric seal (e.g., seal 63of cup 61) around its periphery. The absorbent material should notintrude between the organ and the elastomeric seal, so that a good fluidseal can be maintained by direct contact of the elastomer with theorgan.

The suction member of the invention can be connected to a constant forcespring arrangement which applies a constant retraction force to thesuction member, while still providing rotational and translationalcompliance. For example, in the FIG. 13 embodiment, suction cup 61 isattached to the distal end of cable 64. Support assembly 65 includes lowtension, constant force spring 66. The proximal end of cable 64 isattached to spring 66. Support assembly 65 is designed to be adjustablymounted (preferably with a low profile) to a sternal retractor or otherfixed structure. Assembly 65 and cable 64 support cup 61 (and the organheld by suction to cup 61) with a constant force, while allowing cup 61freedom to swing and rotate relative to assembly 65 and to undergovertical oscillation relative to assembly 65 (e.g., in response tobeating motion of a beating heart).

A constant force spring arrangement which applies a constant retractionforce to a suction cup can also be used in a variation on theabove-described FIG. 1 embodiment. In this variation, the constant forcespring arrangement is coupled between suction cup 1 and the distal endof portion 4B of attachment arm 4 (in place of sliding ball joint 3).The spring is configured to apply a constant retraction force to suctioncup 1, while still providing rotational and translational compliance byallowing the cup to rotate relative to arm 4 and to undergo verticaloscillation relative to arm 4.

In other variations, a set of one or more springs is employed to apply aretraction force (which can but need not be a constant force) to thesuction cup of FIG. 1 or any of the other embodiments of the invention.In one such variation, the set of springs is coupled between the suctioncup (e.g., cup 1) and the distal end of the arm which supports it (e.g.,attachment arm 4). The set of springs allows the cup to verticaloscillation relative to arm 4. Preferably, the set of springs isrotatably mounted to the cup (e.g., by being attached between thesupport arm and a plate, where the plate is rotatably mounted to thecup) so that the cup is free to rotate about a vertical axis relative tothe support arm, as well as to undergo vertical oscillation relative tothe support arm.

In other embodiments, the compliant joint of the invention isimplemented as a universal joint, or a set of two or more universaljoints.

An aspect of the invention is a preferred method for retracting abeating heart in which a suction member (implemented in accordance withany embodiment of the inventive apparatus) is affixed to a heart at aposition concentric with the apex of the heart. Preferably the suctionmember has sufficient curvature to conform with the apex and is shapedto be at least generally symmetric with the apex. Suction is applied tothe heart by coupling the suction member to a vacuum source, and thesuction member is moved to retract the heart to a desired position forsurgery. Preferably, the suction member is mounted to a fixed assembly(e.g., a fixedly mounted sternal retractor) by a compliant joint so thatthe suction member does not constrain normal-beating motion of the heartduring gross movement of the suction member and heart into the desiredposition, and while the suction member supports the heart (e.g., whilethe heart is suspended vertically below the member) in such position. Insuch preferred embodiments, the suction member has an axis of symmetry,and as the heart beats, the heart is free to expand and contract, withthe compliant joint allowing the suction member to oscillate along theaxis of the suction member (e.g., along a vertical axis) and to twistabout the axis (e.g., the vertical axis) relative to the fixed assembly,so that hemodynamic function is not compromised.

Another aspect of the invention is a method including the steps of:

1. placing a suction cup on the apex of the heart, and applying suctionto hold the heart;

2. adjusting an arm (e.g., arm 4 of FIG. 1 or arm 10 of FIG. 2) whichsupports the suction cup (e.g., by sliding arm 10 relative to holder 11,and/or sliding holder 11 relative to element 8) to achieve the desiredamount of retraction;

3. adjusting the arm (which supports the suction cup) to achieve anangle between such arm and the suction cup which allows maximal suctioncup displacement (relative to the arm) to occur with each heart beat;and

4. then, performing surgery on the heart while it is suspended (viasuction) from the cup.

The inventive method and apparatus allows manipulation of a beatinghuman heart so as to expose lateral or posterior coronary arteries forthe purpose of bypassing those vessels.

Since the inventive apparatus does not rigidly constrain the heartmuscle, the invention allows the heart anatomy to retain its naturalshape and performance. The compliance provided by the apparatus isintended to replicate the motion allowed when the heart is manipulatedeither directly by the human hand or by pulling the pericardium.Overall, there are at least three attributes of the inventive apparatuswhich make it a superior organ manipulator with regard to hemodynamicsand overall access and stabilization. These attributes and thecorresponding benefits are summarized in Table 1:

TABLE 1 Attribute Benefit Built in system Less strain on hemodynamicperformance compliance because the heart can beat normally both duringmovement and while being supported in the final manipulated position;Less force is required to hold the heart because the apparatus is notworking against the heartbeat; Attachment with compliance can beachieved in a wide variety of different positions of the heart (or otherorgan). The apparatus pulls Chambers and vessels of the heart are ratherthan pushes not compressed, allowing them to more the organ to closelymaintain their natural shape manipulate the and fill volumes; organVentricles are placed in tension, creating pre-load for contractility.Separation of gross With separate gross stabilization and local(achieved by the inventive apparatus) stabilization with ventricles intension, less local anastomotic stabilization force (to be provided by adevice other than the inventive apparatus) is needed, reducingdeflection of the heart chamber inwards (such inward deflectionundesirably leads to reduced filling); Ease of use; Improvedreliability.

Although preferred embodiments of the invention are methods andapparatus for cardiac retraction during beating heart surgery, otherembodiments are methods and apparatus for retracting almost all otherinternal organs. The size, shape, and material of the suction cupemployed as well as the amount of vacuum applied can be varied to matchthe topology and consistency of the organ tissue. More than one suctioncup at a time can be applied to each organ, to provide greater or morestable manipulation. Multiple cups can be mounted to a single supportstructure (with one or more compliant joints providing compliancebetween each cup and the support structure), and the cups can then beaffixed to the organ in such a way as to retract the organ in a desireddirection without interfering with the natural movement of the organ.Affixing of multiple suction cups to an organ would allow torsion to beapplied to the organ. Organs often must be twisted or rotated for bettertissue presentation preliminary to surgery.

Other alternative embodiments of the invention include multiple suctioncups mounted at the ends of fingers, with the fingers being configuredto fan out and then move together to grip the heart or other organ withnon-slip surfaces. The fingers are mounted on a compliant joint which isin turn supported by a fixed structure (or the fingers themselves havecompliance and function as a compliant joint), so that the fingers donot constrain normal beating motion of the heart (or normal motion ofthe other organ) during gross movement of the fingers and organ into thedesired position or during surgery on the organ held by the fingers.

An example of this class of embodiments will be described with referenceto FIGS. 14 and 15. In the FIG. 14 embodiment, finger assembly 71includes three suction cups 75 and three hinged fingers 72. Each cup 75is mounted at the distal end of one of the fingers. Each finger 72 has ahinge 73 (which is coupled to extension member 76) and another hinge73A, and member 76 is adjustably coupled to a sternal retractor (notshown) or other fixed structure. Extension member 76 is coupled tohinges 73 in such a manner that a user can manipulate member 76 to causehinges 73 to spread fingers 72 (before assembly 71 grips a beating heartor other organ) and then to cause hinges 73 to gather fingers 72 untilcups 75 grip the organ (as shown in FIG. 14). Then, a vacuum sourcecoupled to cups 75 (via suction lines extending through fingers 72 andmember 76) is actuated to provide suction force on the organ. Member 76can then be moved to retract the organ into a desired position forsurgery.

Assembly 71 functions as a compliant joint, in addition to functioningas a set of suction cups, since while assembly 71 grips the organ,hinges 73 and 73A allow fingers 72 to flex in response to normalmovement of the organ (e.g., in response to beating movement of abeating heart). For example, as shown in FIG. 15, when the surface ofheart 9 moves upward (from the lower position shown in phantom view) tothe raised position shown by the solid line, hinges 73 and 73A pivot toallow finger 72 to move (from the relatively more flexed position shownin phantom view) to the relatively less flexed position shown by thesolid lines. This compliance provided by the flexing action of fingers72 allows cups 72 to oscillate in parallel to the axis of member 76 asthe heart beats. Preferably, fingers 72 are coupled to extension member76 in such a manner that assembly 71 has freedom also to rotate aboutthe axis of member 76 (while member 76 remains fixed).

Other examples of embodiments including finger assemblies are variations(on any of the “single suction cup” embodiments described herein whichinclude a single suction cup) in which a retracting finger assemblyreplaces the single suction cup. In variations on such embodiments, theretracting finger assembly does not include a suction cup at the end ofeach finger, and instead each finger has a non-slip surface at itsdistal end so that an organ (e.g., a beating heart) can be gripped bythe non-slip surfaces.

FIG. 28 is a perspective view of another embodiment of the inventivesuction member, which is a variation on suction cup 61 of FIG. 13.Suction member 130 of FIG. 28 comprises flexible bag-like membrane 131(which can be made of plastic film and preferably has its inner surfacelined with absorbent material), and ring 132 around the periphery ofmembrane 131. Ring 132 is preferably made of plastic or silicone, andits inner face supports sealing material (e.g., elastomeric material)which faces the heart and is capable of forming a seal around theperiphery of member 130. The absorbent material which lines membrane 131should not intrude between the heart (being held or moved by suction)and the sealing surface of ring 132, so that a good fluid seal can bemaintained by direct contact of the sealing material with the organ.Suction line 133 is coupled to ring 132, with its distal end sealedaround an orifice extending through ring 132 so as to be in fluidcommunication with the inner surface of membrane 131.

The suction member of FIG. 29 is a variation on that of FIG. 28. Suctionmember 140 of FIG. 29 comprises flexible bag-like membrane 141 (whichcan be made of plastic film and preferably has its inner surface linedwith absorbent material), and ring 142 around the periphery of membrane141. Ring 142 (which is narrower than relatively wide ring 132) ispreferably made of plastic or silicone, and its inner face supportssealing material which faces the heart and is capable of forming a sealaround the periphery of member 140. Suction line 143 is coupled to ring142, with its distal end sealed around an orifice extending through ring142 so as to be in fluid communication with the inner surface ofmembrane 141.

The design of the FIG. 13, FIG. 28, and FIG. 29 embodiments of theinvention (including a flexible film or membrane with a seal around itsperiphery) has several advantages including the following: the designhelps maintain the natural shape of the beating heart at all times tomaintain hemodynamic function; and placement of the suction member atany of various places on the heart (e.g., on the apex, right ventricle,or AV groove) does not detract from or interfere with the mechanical orelectrical function of the beating heart.

FIG. 30 is a perspective view of another embodiment of the inventivesuction member, with a compliant joint for mounting it to a rigidstructure. Suction member 150 of FIG. 30 includes a cup 151, a hollowshaft 153 fixedly attached to cup 151, and fitting 157 (for attaching asuction line to shaft 153). Shaft 153 is oriented with its axis parallelto the central longitudinal axis of cup 151. Conforming seal 152 (whichperforms the same function as does above-described seal 35) is mountedto the distal surface of cup 151. Seal 175 forms a seal with the heart(or other organ) while preventing the organ tissue from being suckedsubstantially into the internal area of cup 151. The concave innersurface of cup 151 (not shown in FIG. 30) is preferably lined with softand absorbent material (preferably non-woven rayon or viscose fabric,but alternatively another material such as gauze or a material of a typecurrently used in neuro-sponges). The absorbent material is preferablycapable of absorbing enough blood and/or other bodily fluid tosignificantly improve traction between the cup and organ, and preferablyalso functions to diffuse the suction exerted by member 150 on theorgan.

Conforming seal 152 is preferably made of biocompatible foam having opencells (to allow slow flow of air through seal 152), except in that ishas closed cells (which define a “skin”) on the distal surface of seal152 (the surface designed to contact the organ).

Still with reference to FIG. 30, compliant joint 154 attached to thedistal end of arm 159 comprises ball 164, socket member 165, and ballconnector 166. Connector 166 is fixedly attached to the distal end ofarm 159. Arm 159 (which can be a locking attachment arm having aflexible state as well a rigid state) has a distal end which is fixedlymounted to a rigid structure (e.g., a sternal retractor). Socket member165 is attached to connector 166 with freedom to rotate relative toconnector 166 about the axis of the distal portion of arm 159. Ball 164is attached to member 165 with freedom to rotate relative to member 165.Ball 164 defines a central channel, and shaft 153 of suction member 150extends through this channel (as shown).

Preferably, spring 156 is positioned around shaft 153 between fitting157 and ball 164. Preferably, spring 156 is compressed by the forceexerted on it by fitting 157 and ball 164, and spring 156 (assumingaxial compression of the spring in the range 0.1 inch to 0.5 inch duringuse) has a spring constant (k) in the range from k=2.5 to k=5.0,inclusive (k=3.8 would be typical). Optionally, spring 156 is omitted.

During beating heart surgery, the FIG. 30 assembly functions as follows.Cup 150 (including shaft 153) is fixedly attached by suction (exertedthrough fitting 157) to the surface of the beating heart, and thus movesas a unit with the beating heart. The weight of the heart causes shaft153 (and the entire cup 150) and ball 164 to rotate as a unit (relativeto member 165) so that shaft 153 is oriented vertically. As shaft 153and ball 164 rotate as described relative to member 165, member 165typically also rotates relative to fixed ball connector 166. In someimplementations, the device is implemented so that rotation of member165 relative to connector 166 occurs only during gross manipulation ofthe suction member (with the heart coupled by suction to the suctionmember). As the vertically oriented shaft 153 oscillates vertically as aunit with the surface of the beating heart, shaft 153 slides (throughball 164's central channel) relative to ball 164 (while the verticalposition of ball 164 is fixed by socket member 165.

Spring 156 damps the oscillating motion of shaft 153 relative to ball164, in the following manner. As shaft 153 slides vertically downwardrelative to ball 164, spring 156 is compressed (converting some of thekinetic energy of shaft 153 into potential energy). Then, as shaft 153slides vertically upward relative to ball 164, spring 156 relaxes(elongates) back to its equilibrium position (assisting in pulling theheart surface upward as some of the potential energy stored in thespring is converted to kinetic energy of shaft 153).

Preferably, socket member 165 includes a pivoting latch 165A which canbe manually rotated between two positions: a first position (shown inFIG. 30) in which it does not prevent shaft 153 from translatingrelative to ball 164; and a second (locking) position in which itprevents translation of shaft 153 relative to ball 164. The pivot aboutwhich latch 165A rotates is attached to member 165, and thus latch 165Ais fixed relative to arm 159 except in that it is free to rotate (as aunit with member 165) about the axis of arm 159's distal end. When latch165A is rotated into the locking position, its free end hooks onto (oris wedged against) fitting 157 so as to prevent translation of shaft 153relative to ball 164.

It is contemplated that surgeons will find it useful from time to time(during beating heart surgery) to move a latch (e.g., latch 165A)temporarily into a locking position to constrain heart movementtemporarily, such as if the surgeon is having difficulty in executing agraft.

Alternative embodiments of the invention include a latch (or othersimple locking structure) other than latch 165A. Each such lockingstructure can be moved between two positions: a first position in whichit allows shaft 153 freedom to translate relative to ball 164 (or moregenerally, in which it allows the suction member freedom to translatealong the suction member's central axis relative to the fixed structureto which the suction member is mounted); and a second (locking) positionin which it prevents relative motion of shaft 153 relative to ball 164(or more generally, in which it prevents relative motion of the suctionmember relative to the fixed structure to which the suction member ismounted). In some such embodiments, a latch (in its locking position)extends between socket member 165 (or an alternative socket memberimplementation) and fitting 157. In other such embodiments, the latch(in its locking position) extends between member 165 (or an alternativesocket member implementation) and cup 151.

FIG. 31 is a cross-sectional view of another embodiment of the inventivesuction member. Suction member 170 of FIG. 31 has a cup portioncomprising a rigid core 172 (preferably made of rigid plastic) and aflexible cup 171 (preferably made of silicone molded over core 172).Rigid core 172 has a shaft portion through which orifice 176 extends,and projections 172A and 172B which extend radially out from the shaftportion. The shaft portion of core 172 is to be mounted through ball 164of compliant joint 154 (or to another embodiment of the compliant jointof the invention), and a vacuum fitting (e.g., fitting 157 of FIG. 30)is typically mounted at the upper end of the shaft (so that cup 170 isfree to translate relative to the ball of the compliant joint, with theconstraint that the ball stops the vacuum fitting at one end of thecup's range of motion and the ball stops upper surface 178 of cup 170 atthe other end of the cup's range of motion).

Silicone cup 171 can be molded over core 172 (which can but need not beformed of plastic), so that core 172 provides axial support for cup 171and so that the shaft portion of core 172 can be attached to a compliantjoint (thereby attaching cup 171 to the compliant joint withoutinterfering with the function of flexible flange portion 171A of cup171). Conforming seal 175 (which performs the same function as doesabove-described seal 35) is mounted to the distal surface of flange171A. Flange portion 171A of cup 171 provides compliance, allowing seal175 to move in the axial direction (the vertical direction in FIG. 31)and lateral directions (perpendicular to the axial direction) relativeto the surface of the heart (or other organ), so that seal 175 canconform to organ surfaces having any of a wide range of sizes andshapes. Seal 175 conforms to and forms a seal with the heart (or otherorgan) while preventing the organ tissue from being sucked substantiallyinto the internal area of the cup. The concave inner surface of cup 171is preferably lined with soft and absorbent material 174. Material 174is preferably non-woven rayon or viscose fabric, but can alternativelybe another material (such as material of a type currently used inneuro-sponges). Material 174 is preferably capable of absorbing enoughblood and/or other bodily fluid to significantly improve tractionbetween the cup and organ, and preferably also functions to diffuse thesuction exerted by member 170 on the organ.

Conforming seal 175 is preferably made of biocompatible foam having opencells (to allow slow flow of air through seal 175), except in that ithas closed cells (which define a “skin”) on the distal surface of seal175 (the surface designed to contact the organ).

In cypical implementations of suction member 170 of FIG. 31, the surfacearea which faces the organ is in the range 0.6–1.5 inch², the vacuumprovided by the vacuum source (via orifice 176) is in the range −65 mmHg to −400 mm Hg (preferably −250 mm Hg to −350 mm Hg. In preferredimplementation, the vacuum provided by the vacuum source is equal (orsubstantially equal) to −300 mm Hg.

A preferred implementation of flexible locking attachment arm 4 of FIG.1 (or arm 159 of FIG. 30) will be described with reference to FIGS. 32and 33. The arm of FIG. 32 includes a distal joint 202, a number of balljoints 203, a housing 205 (whose distal surface abuts the ball joint 203farthest from joint 202), and a flexible cable 200 strung throughelements 202, 203, and 205. Cable 200 has cylinder 201 fixedly attachedat its distal end. A conventional cable length control mechanism,comprising housing 205, knob 204, pin 206, and a bar clamp assemblywhich comprises base 207, foot 208, lever 209, and cam 210 (betweenlever 209 and foot 208), is employed to control the amount of slack incable 200 between distal joint 202 and the distal end of housing 205.When the clamp assembly and knob 204 are manipulated to introduce slackin cable 200, the ball joints 203 have freedom to slide and rotaterelative to each other (and thus the arm has freedom to bend into adesired configuration). When ball joints 203 have moved into relativepositions which give the arm its desired configuration, the clampassembly and knob 204 are again manipulated to shorten the length ofcable 200 between joint 202 and the distal end of housing 205. Suchshortening of the effective length of the cable causes ball 200 to movejoint 202 toward housing 205, thereby squeezing ball joints 203 betweenjoint 202 and housing 205 so as to fix the ball joints 203 in theirdesired relative positions (which in turn keeps the arm fixed in a rigidstate having the desired configuration).

It should be understood that the term “cable” is used herein (todescribe an element of a flexible locking arm) in a general sensedenoting flexible metal cables and wires as well as other flexibleelongated elements capable of being given greater or lesser amounts ofslack to change the arm between rigid and flexible states.

Conventional ball joints (suitable for use as ball joints 203 in FIG.32) are made of stainless steel, and have roughly the same shape as balljoint 203 shown in FIG. 33. This shape includes a convex “ball” surface(at the left side of FIG. 33) and a concave “socket” surface (at theright side of FIG. 33). The socket surface of each ball joint is pressedagainst the ball surface of the ball joint immediately distal thereto,when the ball joints are tightened together to put the arm in its rigidstate. However, the shape of conventional ball joints does not providegood mechanical advantage when the ball joints are tightened together toput the arm in the rigid state. Further, the surface composition (andsmooth texture) of conventional ball joints provides very littlefriction to assist with locking the arm when the ball joints aretightened together.

One aspect of the present invention is an improved ball joint designwhich reduces or eliminates the noted disadvantages and limitations ofconventional ball joints. Ball joint 203 of FIG. 33 embodies thisimproved design. Ball joint 203 of FIG. 33 has shortened length andincreased diameter relative to conventional ball joints. Preferably,ball joint 203's diameter (from top to bottom in FIG. 33) is greaterthan ball joint 203's length (from left to right in FIG. 33). Forexample, the length is 0.345 inch and the diameter is 0.460 inch in apreferred embodiment (or more generally, the ratio of the length to thediameter is at least substantially equal to 0.345/0.460). The shape ofthe socket surface is modified (to be as shown in FIG. 33) to provideincreased contact area between abutting ball and socket surfaces ofadjacent ball joints which are tightened together. Central hole 203Bthrough each ball joint is angled (or tapered) to allow the cable topass through it smoothly and easily (and to improve rigidity in therigid state, since cable length with the improved ball joint design willnot change as much as with the conventional ball joint design duringeach transition from the flexible to the rigid state).

Also, two materials are used in manufacturing the improved ball joint203. The main portion of the ball joint is molded from hard plastic,such as polycarbonate plastic, Ultem (polyetherimide) plastic, or SSTmaterial. Then, a portion 203A of the socket surface is coated withmaterial having greater friction (such as a thermoplastic or siliconeelastomer). This coating of portion 203A can be accomplished byinjection molding the thermoplastic or silicone elastomer into a groove(at the location of portion 203A) in the socket surface of the hardplastic molding. Preferably, portion 203A is an annular (O-ring shaped)region comprising thermoplastic or silicone elastomer material havingShore A durometer in the range 50 to 90. Alternatively, most or all ofthe socket surface of the ball joint is coated with thermoplastic orsilicone elastomer (or other relatively high friction material). Alsoalternatively, all or part of the socket surface of each ball joint(i.e., the part of each concave socket which mates with an adjacentconvex ball surface) is molded with a rough texture which providessufficiently high friction to adequately lock the arm when a convex ballsurface of an adjacent ball joint is tightened against the portionhaving rough texture. An example of the latter embodiment is a variationon ball joint 203 of FIG. 33 which is molded from hard plastic with asmooth (non-textured) outer surface, except that portion 203A of itsconcave socket surface is molded with a rough texture.

In some embodiments, adjacent pairs of the ball joints 203 are made frommaterials having different hardness (so that the harder material wedgesinto the softer material). In one such embodiment (in which it isassumed that the ball joint at the distal end is the “first” ball joint,and the other ball joints are consecutively numbered according toincreasingly proximal position), the even (or odd) ball joints aremolded from polycarbonate plastic, and the odd (even) ball joints aremolded from Ultem plastic.

In a variation on the FIG. 32 embodiment of the inventive flexiblelocking attachment arm, ball joint 303 of FIG. 34 replaces each balljoint 203 of FIG. 32. Ball joint 303 differs from ball joint 203 in thatsocket surface 304 of ball joint 303 has a jagged profile, comprisingcircular shoulders 305. Shoulders 305 are designed to bite into theconvex ball surface of the adjacent ball joint 303, thus increasingfriction between the convex ball surface and the socket surface 304 incontact therewith, to assist with locking the arm when the ball jointsare tightened together. Annular (O-ring shaped) portion 303A of balljoint 303 is optionally made of material which (when in contact with theconvex ball surface of an adjacent ball joint) provides greater frictionthan if portion 303A were made of the same hard plastic material (e.g.,polycarbonate or Ultem plastic, or SST material) as is the rest of balljoint 303. In preferred embodiments, region 303A comprises thermoplasticor silicone elastomer material having Shore A durometer in the range 50to 90 (which is molded into a recess in the remaining portion of balljoint 303).

In another variation on the FIG. 32 embodiment of the inventive flexiblelocking attachment arm (of which a portion is shown in FIG. 38),alternating ball joints 350 (shown in FIG. 37) and sleeves 340 (shown inFIGS. 35 and 36) replace ball joints 203. FIG. 35 is a top elevationalview of sleeve 340, FIG. 36 is a cross-sectional view of sleeve 340taken along line 36—36 of FIG. 35, and FIG. 37 is a side elevationalview of ball joint 350.

Central channel 341 through sleeve 340 is tapered at both ends (asshown) to allow a cable to pass through it smoothly and easily (and toimprove rigidity in the arm's rigid state). The wall of channel 341defines a socket surface at each end of channel 341, with each socketsurface having a jagged profile comprising circular shoulders 342 and343 and indentations 344 (shown in phantom view in FIG. 36). At each endof channel 341, shoulders 342 and 343 and the edges of indentations 344are designed to bite into a convex ball surface of an adjacent balljoint 350, thus increasing friction between the convex ball surface andthe sleeve 340 in contact therewith, to assist with locking the arm whenthe sleeves and ball joints are tightened together.

Central channel 351 through ball joint 350 is tapered at both ends (asshown) to allow a cable to pass through it smoothly and easily (and toimprove rigidity in the arm's rigid state). Ball joint 350 has anannular flange 352 around its periphery, for limiting the freedom of anadjacent sleeve 340 to slide over the outer surface of ball joint 350.Ball joints 350 and sleeves 340 are shaped so as to fit together asshown in FIG. 38, with a cable (not shown) extending through theiraligned central channels 341 and 351. On some implementations of FIG.38, each ball joint is made from a hard plastic having a first hardnessand each sleeve is made from a hard plastic having a second hardness(different from the first hardness) so that the harder material wedgesinto the softer material. For example, the ball joints can be moldedfrom polycarbonate plastic and the sleeves from Ultem plastic (or thesleeves can be molded from polycarbonate plastic and the ball jointsfrom Ultem plastic).

In general, the ball joints (or ball joints and sleeves) used in thelocking arm employed in some embodiments of the invention preferablysatisfy the following criteria: their geometry results in improvedmechanical advantage to achieve greater and more reliable rigidity whentightened together; they allow arm flexibility when loosened relative toeach other; they have low profile; they remove compliance in the armwhen tightened together; and there is increased friction between theabutting ball and socket surfaces when they are tightened together.

A variation on the FIG. 1 apparatus (which includes a built-in forcegauge) will next be described with reference to FIG. 39. All elements ofthis alternative embodiment that correspond to elements of the FIG. 1apparatus are identically numbered in FIGS. 1 and 39, and thedescription thereof will not be repeated with reference to FIG. 39. Inthe FIG. 39 embodiment, ball sliding joint 3 includes (in addition toball 3A and U-shaped element 3C): spring support 300 (connected betweenthe upper ends of element 3C), and spring 301 connected between support300 and ball 3A. Element 3C is marked with a scale 302 which is orientedparallel to one of grooves 3B, and ball 3A is marked with a positionindicator 303. As element 3C moves relative to ball 3A (with ball 3Ariding in grooves 3B), spring 301 compresses or elongates (and thus thespring force exerted by spring 301 on support 300 and element 3Cchanges), and indicator 303 becomes aligned with different ones of theforce index marks comprising scale 302. The relative position ofindicator 303 and scale 302 provides a visual indication of the springforce being exerted at any instant by spring 301 on support 300 (andhence on element 3C). Thus, elements 300, 301, 302, and 303 implement aspring force gauge. The force gauge can be used by the surgeon to helpthe surgeon configure the apparatus so that it exerts safe liftingforces on the heart during use.

Still other alternative embodiments of the invention include abio-absorbable disc with an adhesive surface to be adhered to the heart(or other organ) surface (instead of a suction cup). The disc isreleasably mounted on a compliant joint which is in turn supported by afixed structure, so that the disc does not constrain normal beatingmotion of the heart (or normal motion of the other organ) during grossmovement of the disc and organ into the desired position and surgery onthe organ suspended vertically below the disc in the desired position).The disc is released from the compliant joint after the surgicalprocedure. This can be a variation on any of the embodiments describedherein with the bio-absorbable disc replacing the suction cup. Forexample, the FIG. 27 embodiment includes bio-absorbable disc 141 (havingan adhesive, concave lower surface) in place of cup 41 (and suction line45) of FIG. 7. The FIG. 27 embodiment is otherwise identical to theabove-described FIG. 7 embodiment, and the description of its componentswhich are identically numbered in FIGS. 7 and 27 will not be repeated.

Use of a suction cup in accordance with the invention desirably supportsthe blood flow structures of the heart (or other organ) beingmanipulated to prevent them from collapsing under externally appliedforces (for example, to compensate for compression during stabilizationto permit surgery).

The suction cup of the inventive apparatus can be preformed of hardmaterial (such as hard plastic) or flexible material (such as siliconrubber), with its inner surface lined with biocompatible foam or othermaterials currently used in neuro-sponges (to absorb blood and otherbodily fluid, thereby improving the cup's grip on the heart or otherorgan). To preform the cup in a desirable shape (a shape likely toconform with the organ which it will manipulate), a rubber cast of atypical organ surface can be made and the cast can then be used tomanufacture (e.g., mass produce) the cup, or a typical organ surface canbe scanned with a laser to generate a computer model and the model canthen be used to manufacture the cup.

We contemplate using an auxiliary suction member (with any of theabove-described embodiments of the inventive apparatus which include asuction member and a compliant joint) under some circumstances (such asto perform certain types of heart surgery). For example, when theinventive suction member (with compliant joint) retracts a beating heartby applying suction to the apex of the heart, and the heart is suspended(by suction) below it, an auxiliary suction cup (or other suctionmember) can be affixed to the side of the heart to assist with rollingor moving the heart. The auxiliary suction member could be mounted to ahand-held rigid pole, or to an arm mounted to a fixed structure. Theauxiliary suction member would typically have less curvature (it wouldbe flatter) than any of the above-described suction cups which areespecially designed to grip the apex of the heart. The auxiliary suctionmember would desirably be mounted to a compliant joint (of any of theabove-described types), so that it does not compromise hemodynamicfunction of the organ being retracted.

The invention can be employed to manipulate (and support in a retractedposition) an organ other than a beating heart. For example, it can beused to manipulate (and support in a retracted position) a liver (e.g.,during a cholecystectomy) or a stomach (e.g., during a Nissenfundoplication).

The foregoing is merely illustrative and explanatory of preferredembodiments of the inventive methods and apparatus. Various changes inthe component sizes and shapes, and other details of the embodimentsdescribed herein may be within the scope of the appended claims.

1. An organ manipulation apparatus, including: at least one suctionmember having an inner surface and an outer surface, wherein the suctionmember is configured to exert sufficient suction force on an organ tomove the organ when the suction member is placed against the organ, apressure differential is established between the inner surface and theouter surface, and the suction member is moved; a support structure; anda joint coupled between the suction member and the support structure,wherein the support structure and the joint are configured to supportthe suction member, with the organ supported in a retracted position bythe suction member, such that the suction member has freedom to move atleast along an axis of the suction member relative to the supportstructure.
 2. A method for compliant retraction of a beating heart,including the steps of: (a) retracting the beating heart by exertingsuction thereon using a suction member coupled to a mounting element, insuch a manner that the suction member has freedom to move relative tothe mounting element in response to normal movement of the beatingheart; and (b) maintaining the beating heart in a retracted position byexerting suction thereon using the suction member while said suctionmember is coupled to the mounting element, in such a manner that saidsuction member has freedom to move relative to the mounting element,thereby maintaining beating movements of the heart substantiallyunrestricted.
 3. The method of claim 2, wherein the suction member is asingle suction cup, and step (b) includes the step of suspending theheart from the suction cup in the retracted position using suction insuch a manner that the suction member has freedom to move at leastrotationally relative to the mounting element in response to normalbeating movement of the heart.
 4. The method of claim 3, wherein thebeating heart has an apex, the suction cup is configured to conform toand exert suction on the apex of the beating heart, and step (a)includes the steps of: affixing the suction cup to the heart at aposition of the heart concentric with said apex of the heart; applyingsuction to the heart by coupling the suction member to a vacuum source;and moving the suction member to retract the heart.
 5. A locking armhaving a flexible state and a rigid state for use in an organmanipulator apparatus, the arm comprising: a cable; and joint membersthreaded along the cable, said joint members configured to interfit withone another and lock with respect to one another while in the rigidstate, while being movable with respect to one another while in saidflexible state; at least one surface of two interfitting surfaces of twoof said joint members having a friction enhancing feature to improverigidity of locking between the two joint members when in said rigidstate.
 6. The organ manipulation apparatus of claim 1, wherein saidjoint allows said at least one suction member to rotate relative to saidsupport structure.
 7. The organ manipulation apparatus of claim 1,wherein said joint allows said at least one suction member to translaterelative to said support structure, in directions along a longitudinalaxis of at least one of said at least one suction members.
 8. The organmanipulation apparatus of claim 1, wherein said at least one suctionmember has freedom to move, relative to the support structure, inresponse to normal movement of the organ.
 9. The organ manipulationapparatus of claim 8, wherein the organ is a beating heart.
 10. Theorgan manipulation apparatus of claim 9, wherein the beating heart hasan apex, and wherein the at least one suction member is configured toconform to, and exert suction on, the apex of the beating heart.
 11. Thelocking arm of claim 5, wherein said friction enhancing featurecomprises a textured surface.
 12. The locking arm of claim 5, whereinsaid friction enhancing feature comprises a difference in hardnessbetween compositions of the first and second surfaces.
 13. The lockingarm of claim 5, wherein said friction enhancing feature comprises agroove in at least one of said first and second surfaces.
 14. Thelocking arm of claim 13, further comprising a material filling saidgroove, said material being softer than a composition of the surface inwhich said groove is formed.
 15. The locking arm of claim 5, whereinsaid friction enhancing feature comprises one of said surfaces having ajagged profile comprising circular shoulders.
 16. The locking arm ofclaim 5, wherein said friction enhancing feature comprises at least oneof said surfaces having a portion thereof formed of a material having agreater coefficient of friction than a coefficient of friction of amaterial forming a remainder of said at least one surface.
 17. Thelocking arm of claim 5, wherein said friction enhancing featurecomprises at least one of said surfaces having a portion thereof formedof a material having a greater hardness than a hardness of a materialforming a remainder of said at least one surface.
 18. The locking arm ofclaim 5, wherein said friction enhancing feature comprises a differencein coefficients of friction between compositions of the first and secondsurfaces.
 19. An organ manipulation apparatus, including: at least onesuction member having an inner surface and an outer surface, wherein thesuction member is configured to exert sufficient suction force on abeating heart to move the beating heart when the suction member isplaced against the beating heart, a pressure differential is establishedbetween the inner surface and the outer surface, and the suction memberis moved; a support structure; and a joint coupled between the suctionmember and the support structure, wherein the support structure and thejoint are configured to support the suction member, with the beatingheart supported in a retracted position by the suction member, such thatthe suction member has freedom to move relative to the supportstructure, in response to normal movements of the beating heart.
 20. Theorgan manipulation apparatus of claim 19, wherein said joint allows saidat least one suction member to rotate relative to said supportstructure.
 21. The organ manipulation apparatus of claim 19, whereinsaid joint allows said at least on suction member to translate relativeto said support structure, in directions along a longitudinal axis of atleast one of said at least one suction members.
 22. The organmanipulation apparatus of claim 19, wherein said support structurecomprises an elongated arm.
 23. The organ manipulation apparatus ofclaim 22, wherein said elongated arm is a locking arm having a flexiblestate and a rigid state, said locking arm comprising: a cable; and jointmembers threaded along the cable, said joint members configured tointerfit with one another and lock with respect to one another while inthe rigid state, while being movable with respect to one another whilein said flexible state.